ok so i went to look at a 94 1500 with the 6.5 turbo... it has only 8k on a fully rebuilt motor with all the paperwork to prove it... body has just a little couple of scuffs nothing major... absolutely no rust though... came from texas

the current owner is a diesel mechanic whom went to school and currently works at a reputable shop not to far away... so im guessing he knows his sh*t

so here we go...

first off... the stock exhaust is straight piped where the cat and muffler should be. Also he has the wastegate wired shut... when he started it up i did not hear any turbo whistle at all... and none when he reved it up... and no kind of howling from the exhaust. so i had him take off the elbow and the turbo is very free spinning and no side to side wobble at all... is this all just because of the stock intake box and dirty ass fram paper filter?

second... he bypassed the egr system by taking off the solenoids (thats what he said... not what i saw) and now it throws a check engine light... i kinda dont like how he bypassed it... anyway to bypass this the right way and not get a check engine light? i dont want the check engine light to always be there... nor do i want the computer to hold a code and trip into a default mode for anything...

third... he disconnected the CDR valve from the intake tube... he said that a diesel tech of 30+ years told him that it was not needed on the 6.5 motors... well no big deal cause i will just put a new tube in place of the one he took off... and reconnect it! any reason why some guy would tell him to do this? is there any gain from this with the expense of some engine wear? he said its been like this for about the last 6k miles with no problems...


and lastly... what automatic trans do you think they put in this truck? i know they normaly come with the 4l80E however this is a 1500 and i did not know if it still would come with a lighter duty trans... and does anyone know what kinda gears would come in a 94 1500 2wd x-cab shortbed?

ok so i went to look at a 94 1500 with the 6.5 turbo... it has only 8k on a fully rebuilt motor with all the paperwork to prove it... body has just a little couple of scuffs nothing major... absolutely no rust though... came from texas

the current owner is a diesel mechanic whom went to school and currently works at a reputable shop not to far away... so im guessing he knows his sh*t Based on the rest of your post, I can't quite agree.

so here we go...

first off... the stock exhaust is straight piped where the cat and muffler should be. Also he has the wastegate wired shut... when he started it up i did not hear any turbo whistle at all... and none when he reved it up... and no kind of howling from the exhaust. so i had him take off the elbow and the turbo is very free spinning and no side to side wobble at all... is this all just because of the stock intake box and dirty ass fram paper filter?
The wastegate should not be wired shut. Very bad idea, especially if you chip it. Does it have any gauges? It is normal to have very little turbo whistle though, but there is normally some, especially with straight pipe. Are you sure the gate is wired shut and not open?

second... he bypassed the egr system by taking off the solenoids (thats what he said... not what i saw) and now it throws a check engine light... i kinda dont like how he bypassed it... anyway to bypass this the right way and not get a check engine light? i dont want the check engine light to always be there... nor do i want the computer to hold a code and trip into a default mode for anything...
Best way would be a reflash and/or simply blocking the EGR tower or ports.

third... he disconnected the CDR valve from the intake tube... he said that a diesel tech of 30+ years told him that it was not needed on the 6.5 motors... well no big deal cause i will just put a new tube in place of the one he took off... and reconnect it! any reason why some guy would tell him to do this? is there any gain from this with the expense of some engine wear? he said its been like this for about the last 6k miles with no problems...
Normally, a Diesel engine will be vented to atmosphere, however, that's normally on much slower revving engines. Most higher revving engines, like the 6.5, have a CDR, and have it for a reason. It puts a vacuum on the crankcase to prevent leaks.


and lastly... what automatic trans do you think they put in this truck? i know they normaly come with the 4l80E however this is a 1500 and i did not know if it still would come with a lighter duty trans... and does anyone know what kinda gears would come in a 94 1500 2wd x-cab shortbed?
Likely 4L80E, probably 3.42, maybe 3.73.


Answers are above in red.

There are RPO codes in the glovebox that can be searched in the sticky section here that will give you lots of info as to what came stock on the truck, however that could be wrong of any prev owner replaced the stuff but that is a good place to start.
As for the whistle, these trucks do not have alot of it but there should be some especially if it has been straight piped with NO muffler. wiring the wastegate shut can be hazerdous and as far as the cdr valve, that is optional or by preference.

now what the differance of a heath turbo master or just wiring it shut?

now what the differance of a heath turbo master or just wiring it shut?

Wiring it shut does just that, wires it shut. The Turbomaster is a spring that holds it shut until the turbine drive pressure overcomes the spring and forces the wastegate open. It is very possible that the wired shut gate could be causing SES and defuel too. I like the stock system best, myself, since it takes a lot into consideration and actually controls boost pressure, the Turbomaster controls drive pressure. I am definatly a minority in my support of the vacuum system though.

Wiring it shut does just that, wires it shut. The Turbomaster is a spring that holds it shut until the turbine drive pressure overcomes the spring and forces the wastegate open. It is very possible that the wired shut gate could be causing SES and defuel too. I like the stock system best, myself, since it takes a lot into consideration and actually controls boost pressure, the Turbomaster controls drive pressure. I am definatly a minority in my support of the vacuum system though.


funny you mention the SES light and the wastegate wired shut... the light does not come on after you start it up... it comes on after you start it and then give it a lil rev... and comes on right away.

funny you mention the SES light and the wastegate wired shut... the light does not come on after you start it up... it comes on after you start it and then give it a lil rev... and comes on right away.


does that sound like what could be tripping the SES light guys?

It's possible but not likely imo. The turbo won't put out any boost to speak of until you get the engine under load. You need to pull the codes and see what's tripping it.

It's possible but not likely imo. You need to pull the codes and see what's tripping it.

I know there could be alot of things causing the SES light but from what he has posted in the beginning, my vote is for the EGR bypass ("mickey mouse" style from what I understand) From what I have read on this site, if not bypassed properly (ECM reflash / chip) there will always be a SES light come up. Some are just willing to deal with it or remove the bulb (which I do not recommend but thats my preference) You just have to check the codes now and then to be sure nothing else has come up.

You are right plling the codes is the thing to do so you KNOW what is going on.

I know there could be alot of things causing the SES light but from what he has posted in the beginning, my vote is for the EGR bypass ("mickey mouse" style from what I understand) From what I have read on this site, if not bypassed properly (ECM reflash / chip) there will always be a SES light come up. Some are just willing to deal with it or remove the bulb (which I do not recommend but thats my preference) You just have to check the codes now and then to be sure nothing else has come up.

You are right plling the codes is the thing to do so you KNOW what is going on.

Yup. Any number of things it could be, likely multiple things. Only way to know 100% is to pull them, which is very easy with a paper clip (see FAQ).

well im going to his house on saturday... ill pull codes then... he only wants 3000 for the truck and it really is in great condition! something tells me he really needs the money and thats why he is selling so cheap... ill just do the little fixin like the CDR valve and a turbo master... and eliminate the EGR the right way... or maybe just reconnect it all up...

what would you guys do? rid of the EGR system or make it work?

Truck prices must be alot higher down there that's about all you could get for one up here that ran good no issues.

here are some pics of the truck...

http://i30.photobucket.com/albums/c341/layinrockers10/kdk_0012.jpg


http://i30.photobucket.com/albums/c341/layinrockers10/kdk_0013.jpg


http://i30.photobucket.com/albums/c341/layinrockers10/kdk_0011.jpg

he fixed the EGR system and no check engine light! so ill be putting her on the road this week... then ill take a 10 minute drive over to SS DIESEL for the stainless 4 inch exhaust with the crossover and #9 resistor! that should make for a little pep in its step!

Nice looking truck, hope you have many miles & smiles :thumb:

Post back after you get the 4" exhaust, give us your thoughts...